The potentials of our concrete

Given that Bendt and I have written not a few of the blog posts available here on Hi-Cons UHPC blog, we decided it would be appropriate to explain why we dare to repeatedly waste your time with our tales from the world of UHPC – what qualifies us to have a public opinion on UHPC? What is the story behind the faces?

A 20 year-long crush on UHPC, aesthetic concrete and development

– By Tommy Bæk Hansen

For myself my affair with concrete, and UHPC in particular, started at Aalborg University while studying to be a structural engineer. Here I was fortunate to meet a very inspiring professor, Per Freiesleben Hansen, to whom I must credit my interest and passion for material science, and concrete technology in particular. Per Freiesleben Hansen sadly passed away in 2002, but his extremely pedagogic textbook “The science of construction Materials” has been translated to English and is available for purchase in online bookstores.

So for my Master’s thesis a fellow student and I ended up working a full year both theoretically and experimentally on fire exposed UHPC, on a binder composition very close to the CRC i2® we currently are using here at Hi-Con. During this I learned a lot, both regarding the material and the intricacies of structured testing and analysis. During this time, I also had the pleasure of several sparring sessions on material technology and CRC with the inventor of CRC, Hans Henrik Bache (Bache since passed away in 2017). I completed my Masters in 1997.

I apparently did something right, because following this, I was offered a position as an industrial Ph.D. student in a cooperation between the cement company Aalborg Portland, Aalborg University and the ready-mix company Unicon, to continue the investigations on the thermodynamic behavior of dense cement-based materials at elevated temperatures. In addition to Per Freiesleben, I gained much from my advisor at Aalborg Portland at the time, Dirch Hans Bager who in 2016 sadly also passed away.

I learned much about the rheology, the curing processes and how to manipulate these during this time, but also got a healthy dose of advice on practical application from the cooperation with Freddie Larsen at Unicon. Freddie, I’m happy to report, is still very much alive and has just celebrated his 72 birthday!

I completed my Ph.D. in 2001, having worked 4 years on UHPC, but given that at this time, UHPC application was still in its infancy – Hi-Con incidentally was founded just that year – my work took a different direction: Concrete aesthetics.

At this time, Aalborg Portland, through its brand Aalborg White, launched its strategy to be the worlds leading white cement supplier, and consequently a lot of effort at the R&D center was being focused at the limiting factors for white cement application. A major one was aesthetic durability of light-coloured concrete.

 
Tommy Bæk Hansen sharing knowledge with colleagues from Sweden, Norway and Finland

At the time, this field of research was quite virgin as a research topic world-wide, so it was interesting and challenging to be given a job as research engineer with the task of finding relevant literature, conduct field studies, develop, build and test methods to investigate aesthetic durability experimentally etc. In total, I ended up spending almost 8 years on the aesthetic aspects of white concrete application at Aalborg Portland – knowledge I now use to improve the aesthetic qualities of Hi-Cons products and give advice to our customers and end users when things get difficult. In parallel, I spend much time looking at white cement properties in many different applications, in combination with a multitude of additives, and under different climatic and cultural conditions as part of the Aalborg White Technical Team, aiming at assisting clients in developing, transferring and expanding white cement applications world-wide. I did this work in cooperation with Hans Bruun Nissen, now head of the Business Development Team at Hi-Con.

During these years, Aalborg Portland was bought by the Italian company Cementir (in 2004), and a series of cut backs and rationalizations were executed, leading to the white cement strategy being put on hold in 2008. At this point, I was directed into a role as project portfolio coordinator, to facilitate alignment between Aalborg Portlands many development projects and changing strategic focus.

At this point I felt I was drifting away from my main interest in material science and advanced concrete technology, and therefore was very happy when the opportunity to be part of Hi-Con arose. I started up at Hi-Con June 1st, 2010.

During my 7 years at Hi-Con I have managed 100+ commercial projects, assisted in Hi-Cons start-up in Holland, Norway, Sweden and Finland by executing lead projects incl. securing approvals with local municipalities, and training local cooperation partners in design and production of CRC i2® elements. The projects have been within mainly housing (both new build and renovation), but also includes infrastructure and urban applications. Parallel to this I have conducted numerous R&D projects for the purposes of increasing Hi-Cons internal knowledge or provide specific documentation both internally and with external cooperation partners.

Tommy Bæk Hansen and project manager, Frederik Boysen working on the R&D project: Cold bending

So, what do I bring to the discussions of UHPC that merits your continued attention?

In my own humble opinion, I think the most important contribution I can offer, is my curiosity and a desire to keep challenging design and production principles in UHPC applications, and to openly discuss the strength and weaknesses of different UHPC solutions.

Having an open dialogue, also discussing more painful issues, such as need for repairs, lime efflorescence or possible fiber corrosion, is in my opinion the only way to conduct an honest debate and develop better solutions to the benefit of the users of Hi-Cons UHPC products.

I hope you agree and will keep reading my posts!

If you have questions feel free to post a comment below, as always.